“Difficult temperament traits early in life are related to later mental health and childhood behaviour problems.

“Improving support to women stressed during pregnancy could benefit their unborn child, as the womb environment is one of the earliest influences on infant temperament.”

Researcher Dr Gabrielle Simcock said high levels of maternal stress affected girls’ problem-solving abilities more than boys, and girls also demonstrated poorer cognitive and motor development skills.

“Prenatal stress was further linked to lower scores in two-year-olds’ abilities to understand and predict another person’s emotions and behaviours – which could cause later problems with their ability to engage socially with others,” Dr Simcock said.